Process of coking coal



Dec. 22, 1936; c. one I 2,065,288

PROCESS OF COKING COAL Filed July 1, 1951 3 Sheets-Sheet 1 Fig. 1

INVENTOR- ATTORN EY 3 Sheets-Sheet 2 'C. OTTO PROCESS OF COKING COALFiled July 1, 1951 Dec. 22, 1936.

INVENTOR Di in 1 ll/WI? Dec. 22, 1936. c OTTO 2,065,288

PROCESS OF GOKING COAL Filed .July 1, 1931 3 Sheets-Sheet 3 Fig.1 4

INVENTOR Ca -6% ATTORN EY Patented use. we Y UNlTED STATES messesraoosss or come cost; Carl magnum-nun, Germany Application July 1, 19 ii InGermany :1, sun] No.- 548.201 my 1, 19:0

10mm (01. soc-st) The invention has ior its object a coking process tobecarried into eflect in intermittently operatingcoking chambers in whichprocess at the beginning of the. coking Period the 5 gases produced. aresucked out oi the interior of the charge in .such a manner that, inaddition to a considerably increased yield of light oil and primary taran improvement of the -qual-- ity of. the coke 'is attalned moreparticularlywith coal sorts which have only little tendency .to baking.'With these ends in View, the suction of the 'gasesof distillationproduced at thev beginning of the coking period irom the interior of thecharge is carried through in such a manner that formation of a-cokingseam is avoided or that such formation .at least occurs to a verysmaller extent than hitherto. The measures taken for this purpose anddescribed hereinafter are based on the hypothesis that the coking seamis due to deposition of vaporous products oi distillation on coalparticles which are cooler than the products.

According. to the invention this condensation and deposition of products01' distillation is avoided by either notably increasing the velocity 4of the escaping products of distillation or increasing their temperaturebeyond their point a seam already formed upon the escapement oithe-distillation gases, according to the invention the distillationgases are drawn on! from the coking chambers,.the charge. of which isstill,

inth'e ilrststage of the coking period, by'means of pipes projectingintoi-the charge' and under.

so high a above atmospheric that'n'o higher pressures in the upper gascoilecting spaces oi-thewhambers than inthe' 5 adjacent heatingwalls.,.i 'lhe pressures required .ror this me s in with'the results.

' or the amount toatleastzoo min. water. but are Furthermore, aswith-pressures "of this height ine-mus existing between the heatingilues made of silica brickwork areno longer-gas-tight, and care hasto betakenthat no substantially lower pressure prevails in chambers in the 55vicinity of these walls than in the adiacent heattlally eliminate thenoxiouseifectot .a coking.

. these coking chambers are supplied together with 4 6 oil thedistillation-gasesiromlthe chamber. In and the chambers. which arenormally ing'fiues." Hence, in practice it is to provide a regulatingdevice by which the power of the gas suctionis regulated in sucha.-manner, for instance by means of a valve inserted in the suctionconduit, that in the vicinity of 5 the chamber side 01! the walls thatseparate the coking chambers from the heating flues ;neither a notablyhigher. nor a notably'lower pressure will prevail than-on the ,side ofthe heating flues. This regulating-device is actuated suitably'in amanner as to r spond to the difierence of. pressure existing between theupper gas collecting spaces oi. the cokingicharhbers "and theneighboring- Such a. regulating device is requiredparticularly becausethe resistance the'cake oilers to the gases passing therethroughconsiderably varies during a the coking period. 7

- A. further possibility of avoiding formation oi a coking seam or tonotably reduce its disad-. vantageous eilect may consist in introducinginto the chambers a hot gas which together with the products ofdistillation generated is sucked oil through the above pipes whichproject into the charge, this mixture of. introduced and distillation.gas then having such temperature that ithas no tendency to condense evenwhen pass.- ing through cooler coal =0! the charge.

Furthermore, instead oi introducing superheated steam. hot water'gas' isalso well 3 to realize this portion oi the invention, and moreparticularly even water gas the carbon of whichhasnotyetbeenlargeiyreduc'ed. 'lhewater gas may be supplied'eitherby'a'special producer or better from cokingchambers-oi the same batteryin-which the charge has already completely.burned oil and wherein thewater 8 s Droducedby blowing in steam. In way also the hotdistillatiomgases producedin the water-gas thus. produced; therein tothe battery lnwhich the charge in the first l'tagefilthe cokingor vaporsare-supplied either through'the uppergas collecting of the chamber orbetter pipes which likewise project intothe charge have openingswhichpipes maybe designed like those serving to draw thismanner oi-operation'two seals may be made useot, the one oi-whichthroush pixies nroiectmginto the charge draws oil distillation gases from. the chambers the orwhich isain the ilrst stage cl the coking pgridlli while other 55 orauxiliary seal merely serves to establish a communication between theupper gas collecting spaces of the chambers the charge of which is inthe last coking stage and the members that feed these hot gases to thechambers the charge of which is still in the first coking stage.

The suction of the distillation gases as well as the supply of the hotscavenging gases may be effected by known horizontal or vertical pipes.During the last stage of the coking period the suction pipes may alsoserve for the introduction of steam into the chambers for the generationof the water gas. If vertical suction pipes are to be provided for,these pipes may be introduced into the chamber through apertures thatcan be completely gas-tightly shut off. These apertures are provided inseries in the oven cover in the central plane of the chamber between thecharging holes. After the chamber has been filled suitable rods arepushed down into the fresh charge by which rods passages are preparedfor the pipes and which preferably are mounted on the larry car of thebattery and manipulated from the latter, the whole system of pushingrods and their actuating mechanism advantageously being designed so asto be rocked or lifted into an inoperative position in order to permiteasy travel of the larry car. As a matter of course, however, thepushing rods together with an actuating mechanism hereinafter describedmay be mounted on ajspecial car travelling on the track of the larrmcar.

After vertical passages have been formed in the charge by the aid of theabove pushing rods, the suctiorifpipes are lowered into these passagesso as to .ptoiect partly thereinto. In order to attain me..- 0st uniformpossible suction in the verticaldirection, the vertical suction pipesmay have different lengths so as to project into the charge to diiferentdepths.

Furthermore, in order to attain a. close contact'of the coal with thesuction pipes, the latter may be introduced into the charge togetherwith the pushing rods. After this introduction the rods are removedwhile the suction pipes remain in the charge.

The connection of the suction pipes of each chamber with the common highquality gas seal is advantageously established by providing fixedconduits on the apertures of the oven cover which conduits lead to amain above each chamber serving to draw of! the whole distillation gasesof a chamber and are connected to the primary tar seal, a valve beingprovided in each of these conduits. These mains may also be connected tothe conduit that feeds superheated steam, so that when going over fromthe suction of primary tar to introduction of steam, only reversal ofthe valve is required, whilst the apertures in the oven cover can remainclosed and gas tight.

In order that the heavy hydrocarbons drawn of! during the first stage ofthe coking period are not exposed to cracking, the temperature in allthe conduits must not exceed a determined degree, and the suction meansare therefore cooled.

Inorder to cool the suction device cooling members may be provided inthe suction pipes. Thwe cooling members preferably consist in porouscylinders of ordinary or fire clay to which water is fed dropwise inregulatable quantities. The water then evaporates on the large surfaceof the cylinders to which thus can be given an exactly determinedtemperature so that the suction pipes can be kept cool in any desireddegree. The pipes must of course not become too cold as otherwise thehigh boiling hydrocarbons would condense and return to the cokingchamber.

In order that the invention may be clearly understood and readilycarried into effect, an embodiment of the same is illustrated by way ofexample in the accompanying drawings in connection with a chamber ovenadapted for the realization of the process according to the invention.

Figure 1 is a vertical sectional view thru the 7 top of a cokingchamber.

Figure 2 is a vertical section thru the top of a chamber showing a formof carrying car for the pusher rods.

Figure 3 is a sectional view through a coking chamber, showing anotherform of means for carrying out the invention.

Figure 4 is a front view of the chamber shown in Figure 3.

Referring first to Figure 1 which is a view of the top portion of acoking chamber, I denotes a coking chamber and la the coal charge to becoked in the chamber. The chamber is closed by the usual doors 2.Vertical passages 3 in the charge thru which the distillation gases aredrawn off during the first stage of the coking period and thru whichsteam may be later introduced. The larry car 5 travels on the track 4and through the hoppers 6 of the car coal is supplied to the chamberthrough the charging holes 1. After opening the closures 8, the pushingrods 23 (shown in Figure 2), are introduced through the apertures llprovided in the top of the oven. The pushing rods prepare the abovepassages 3 in the coal charge. After removal of the rods or alsodirectly with their introduction the pipes 9 are suspended from theapertures H which pipes are arranged in a row in the longitudinaldirection of the chamber and serve first to draw off the distillationgases and later on to supply steam. Within the pipes 9 are mounted theabove-described cooling members ID. The apertures II which enlarge inupward direction, are connected by pipes ii to a collecting main 13which according to the position of the valves ll and I5 is incommunication either with the seal I! or with the steam collectingconduit II. The valve i4 is automatically controlled in a manner notshown by a controlling mechanism operating in response to the differenceof pressure and communicating both with the gas collecting space I! of achamber and one of the adjacent heating walls of the said cokingchamber.

The gas collecting spaces I! of all the chambers of a battery areinterconnected by a conduit l6 running within the oven cover in thelongitudinal direction of the battery which con- I duit normally isclosed by plugs It. By means of valves (not shown) the conduit Ii can beshut oi! fromall but one of the gas collecting spaces It. These otherspaces It have to be shut 0153 especially when their doors 2 are to beremoved in order to push the respective charge. The conduit It serves tosupp y steam after it has been introduced according to the inventionthru the pipes 9 during the last stage of the coking period, or amixture of steam, water gas and distillation gas, to the chambers inwhich the charge is still in the first coking stage, whereby anaccelerated expulsion of the'heavy hydrocarbons is attained. Thedistillation gases developed during the last coking stage are thus drawnofl? immediately from'every chamber into main [6 andarrive in the seall9 only by passing. through the collecting main l6 and through thosechambers the charge of which is still in the first coking stage. Bysuitably governing the coking process and the provision of a powerfulsuction in the individual chambers no formation of any coking seam atall occurs, as hitherto, that is the coking seam hitherto formed in thevertical central plane of the charge does not appear. On the contrary,solid coke blocks extending from the one chamber wall to the other areformed. In this way the possibility is given of production of large cokealso in very narrow coking chambers; and of a considerable reduction ofthe duration of the coking period. Furthermore, because of the fact-thatby the introduction of steam partial cooling of the charge is attainedwithin the chamber, a smaller quantity of heat is lost by the coke lateron .being quenched; the heat economy of an oven plant designed accordingto the invention thus being better than hitherto. Finally, this coolingof the coke within the chamber further favors the formation of largecoke blocks, as it has been observed that a coke that already has beencooled partly within the chamber forms larger pieces than a coke whichis pushed when still in a very hot state.

In Figure 2 isillustrated by a view of a suitable embodiment of a carcarrying the system of pushing rods and appurtenant actuatingmechanisms.

The illustrated car 20 travels on the track 4 of the larry car of thebattery. 23 denotes the pushingrods which are vertically movablyarrangedin guide tubes 23. These tubes have longitudinal slots throughwhich project lugs 2| 'flxedon the respective pushing rods 23 andserving for the attachment of an endless actuating cable or chain 2|which runs on suitable pulleys or sprocket wheels 22, 22'. The pulleysare driven by a motor (not shown) mounted on the car 20. In this way therods 23 are pushed into the charge or lifted therefrom.

The improvement of the quality of the tar as aimed at by the invention"as well as the increased yield of tar and light oil is warranted only ifthe weakening of the coal is not accompanied' by a quick increase oftemperature so .5 that the heavy hydrocarbons generated are not "55exposed to high temperatures. In connection with a slow increase oftemperature the invention further provides that. the resistance offeredto' the distillation gases by a coking seam which maybe is formedremains small. To this .end

according to the invention the heating of the coking chambers isregulated in such a manner that during the distillation when gases aresucked oil from the midst of the coke cake.

all portions of the charge, including those situ- C. usual in the hightemperature coking process,v

whilst much lower temperatures prevailed in the midst of the cake.According to the invention the temperature of the portions of the chargein the vicinity of the heating walls is maintained below 700 C. untilthe coal has gone over throughout'toplastic state and as long as thedistillation gas is still being sucked off from the midst of the coalcake.

- The means to be provided for maintaining the temperature of allportions of the charge below 700 C. may be of various nature. It isobvious so to heat the'heating walls that only little gas is fed duringthe first hours of the coking period. For this manner of operation,however, it is necessary that the two coking chambers beside a heatingwall are emptied and re-filled only in short intervals or that eachheating wall is subdivided into two parallel rows of heating flues. Itis possible, however, to maintain a uniform heating and to attainnevertheless the desired low temperature of the coal portions situatednear the heating wall by properiod may take place through. horizontal orvertical pipes in lieu of through the upper gas ,collecting space, whichpipes project into the charge.

The Figures 3 and 4 show embodiments of this type; Figure 3 being afragmentary view through a coking chamber, while in Figure is thecorresponding front view. 'Ihe'upper gas collecting spaces of thechambers which are in the last coking stage can be connected with anauxiliary seal from which the hot distillation gases or a mixture ofdistillation gas, steam and water gas can be supplied to the chamberswhich are in the first coking stage by special pipes projecting into thecharge.

In additionto the seal 24 which by a vertical pipe 25 and a bent pipe 26is connected to the upper gas collecting spaces of the chambers of abattery and'can be shut oi! therefrom, and to the collecting pipes 2Iwhich likewise can be shut off by valves 28, an auxiliary seal 29 is tovertical pipes II extending between the chemher doors which pipes can beshut oil by valves 32. Horizontal pipes provided with perforations maybe introduced through the chamber doors 33 which pipes, according towhether they are to serve for sucking of! the distillation gases or forsupplying the hot steam-water gas mixture,

are connected with either the ascension pipes 21 or 3|, by means of thebent pipes 34.

All or part of the horizontal pipes may be connected to steam collectingconduits (not shown) after the coking process has already made progress,while the ascension pipes 25 remain shut of! during the entire cokingperiod. P In thiscase the distillation gases are drawn oi! from thebattery merely through those of the horizontal pipes which through. theascension pipes 21- are in connection with the hydraulic main 24. whilefrom those chambers to which steam is' fed through the horizontal pipesthe mixture of distillation gas, steam and water gas arrives through theupper gas-collecting space in the auxiliary main 29 from where itis fedthrough the ascension pipes 3| and the horizontal pipes-attached theretoto the coking chambers the charge of which is in the first stage of thecoking period, where it acts as scavenging gas and prevents condensationof constituents of the distillation gas and their deposition onto thecoal particles and thus formation of a coking seam.

In Figure 3 only three horizontal pipes one above the other are shown,it will, however, be

of advantage to provide a greater number of such pipes in order toattain a more uniform penetration of the charge of the' hot scavenginggases and a more effective suction of the distillation gases, the mutualdistance of the pipes in a vertical direction then being not greaterthan about half of or the whole width of the chamber.

Should horizontal pipes be used, it is advantageous to alternatelydispose between two neighboring chamber doors the ascension pipesserving to draw oil the distillation gases and those serving for thesupply of the scavenging gases, as illustrated in Figures 3 and a.

What is claimed is:

1. The batch process of coking coal in a coking chamber provided withheating walls which comprises charging the chamber with coal, providingpassages in said charge leading to the interior thereof, externallyheating the charge thereby carbonizing the coal, drawing offdistillation gases by, suction from the interior of the charge thru saidpassages during the first coking period, and introducing scavenging gasinto said chamber during the first coking period, the temperature ofsaid gases being more than 500 centigrade.

2. The batch process of coking coal in coking chambers provided withheating walls, which comprises charging the chambers with coal,providing passages in each charge leading to the interior thereof,externally heating the charge thereby carbonizing the coal. drawing onthe distillation gases by suction from the interior of each charge thrusaid passages during the first coking period, and drawing off the gasesfrom chambers during the last coking period and supplying said gases toother chambers in which the charge is in the first coking period.

3. The batch process of coking coal in a coking chamber provided withheating walls, which comprises charging the chamber with coal, providingpassages in said charge leading to the interior thereof, externallyheating the charge thereby carbonizing the coal, supplying gas to thechamber during the first stage of the coking period therein at atemperature in excess of 500 C., drawing oif distillation and suppliedgases during the first stage of the coking period from the interior ofthe charge by suction, and admitting steam to said charge during a laterstage of the coking.

4. The batch process of coking coal'in coking chambers provided withheating walls which comprises, charging the chambers with coal,providing passages in each charge leading to the interior thereof,externally heating the charge thereby carbonizing the coal, drawing ofl.distillation gases from the interior of the charge of at least onechamber by suction during the first stage of the coking period,admitting steam to said chamber during a later stage of the cokingperiod thereof, drawing oif the distillation gases and water gasgenerated in the chamber in" said later stage, and supplying the gasesso generated to another chamber in which the charge is in the firststage of the coking period.

accuses 5. The batch process of coking coal in coking chambers providedwith heating walls, which comprises charging the chambers with coalsuccessively, providing passages in the charge in each chamber leadingto the interior thereof, externally heating each charge therebycarbonizing the coal, supplying gas to each chamber during the firstcoking period of the charge therein, drawing off the distillation andsupplied gas from each chamber by suction during the first coking periodof the charge therein, introducing steam into the said passages of thecharge in each chamber during a later coking period of the chargetherein, and withdrawing the gas formed in each chamber during saidlater coking period, and utilizing the gas withdrawn from chambersduring the later coking periods therein as the gas supplied to chambersin which the first charge coking periods are then occurring.

6. A batch process of coking coal in a horizontal coking retort ovenstructure comprising a plurality of coking chambers and heating wallsalternating therewith and formed with openings in the top wall of eachchamber distributed along the length of the latter, and with horizontalchannels in the upper portion of said structure extending longitudinallyof the chambers and individually adjacent to and communicating with thetop wall openings of one of said chambers, and formed with a horizontalpassage in the upper portion of the structure extending transversely ofsaid chambers and communicating with each chamber at its top, whichprocess comprises successively charging the different chambers with coalso that the coking operations in the different chambers may begin andend at difierent times, and so as to leave a gas space at the top ofeach chamber above the charge therein, providing vertical passages inthe charge in each oven, one beneath each of the openings in the topwall thereof, connecting each of the top wall openings of each chamberwith the subjacent passage by a conduit traversing the said gas space inthe chamber, externally heating the charge in each chamber therebycarbonizing the coal therein, drawing off distillation gases by suctionfrom the interior of the charge in each chamber during the first cokingperiod therein, through the passages in the last mentioned charge andthe communicating conduits, openings, and channel, and during the final.coking period in each chamber, supplying superheated steam to the chargetherein through the said passages in the charge and the communicatingconduits, openings, and channel, and regulating the pressures in the gasspaces in the different chambers so as to createa gas flow between thelatter through said horizontal passage into and out of each chamberduring the flrst and final coking periods therein, respectively.

7. A process of coking coal in a horizontal coking retort oven structurecomprising a plurality of coking chambers and heating walls alternatingtherewith, which consists in charging the different chambers atdifferent intervals and so as to leave a gas space above the charge andcoking the charges therein in approximately the same coking time so thatat any one time the coking operations in diiferent chambers are indifferent stages, withdrawing the distillation gases from each retortduring an early stage of the coking operation therein by applyingsuction to the interior of the charge therein and thereby creating a gasflow to the interior of 76 aooaaas.

from the said spaces in retorts in which the coking operations are inlater stages without significant change in gas pressure into the saidspaces of the retorts in which distillation gases are being withdrawnfrom the interiors of the charges as aforesaid, whereby the gaspressures at the surfaces of the charges in the different retorts areequalized and the gases passed into retorts in which the cokingoperations are in their early stage, serve in the last mentioned retortsas scavenging gases drawn into the charges from thesurfaces of thelatter.

CARL OTTO.

